This is from two years ago but it’s amazing enough to point and exclaim at now – naturally occurring mechanical gears. Phys.org had the story (the beginning of the sentence is missing for some reason):

a plant-hopping insect found in gardens across Europe – has hind-leg joints with curved cog-like strips of opposing ‘teeth’ that intermesh, rotating like mechanical gears to synchronise the animal’s legs when it launches into a jump.

The finding demonstrates that gear mechanisms previously thought to be solely man-made have an evolutionary precedent. Scientists say this is the “first observation of mechanical gearing in a biological structure“.

Through a combination of anatomical analysis and high-speed video capture of normal Issus movements, scientists from the University of Cambridge have been able to reveal these functioning natural gears for the first time. The findings are reported in the latest issue of the journal Science.

Credit: Malcolm Burrows/Gregory Sutton

How about that?

“In Issus, the skeleton is used to solve a complex problem that the brain and nervous system can’t,” said Burrows. “This emphasises the importance of considering the properties of the skeleton in how movement is produced.”

“We usually think of gears as something that we see in human designed machinery, but we’ve found that that is only because we didn’t look hard enough,” added co-author Gregory Sutton, now at the University of Bristol.

“These gears are not designed; they are evolved – representing high speed and precision machinery evolved for synchronisation in the animal world.”

It’s only the juveniles that have them; they’re lost in the transition to adult stage.

H/t Josh Larios